I've chronographed the loads and looked for pressure signs. I used R15, and H4895. I compared 150 and 170 grain loads to the Flex tip. I was surprised to see that the flex tip magnum load is some 8 grains or so less than even other 170 grain bullets. I know bearing surfaces etc and paid attention. Bottom line, I went over their listed max, with no primer cupping, backing out, extractor marks, case head expansion etc, and got a lot better velocity with a load that appears to give no pressure signs at all. No idea why they list it as so weak.